While it is true that past performance is no guarantee of future results, this piece describes his long professional experience with similar situations, where his reporting was first denied, later shown to be true and even got journalistic prizes for it.
That means he’s more likely than average to be right. He has his reputation at stake, and experience vetting anonymous sources.
It is quite noticeable that the more recent stories by Hersh are entirely based on anonymous sources. And e.g. with the Nordstream article there were quite a few specific facts that were immediately called into question as they contradict public knowledge.
Proof by authority?
> I’ve been told my stories were wrong, invented, outrageous for as long as I can remember
That doesn't mean that every story by him that is called wrong is right.
> What you’ll find here is, I hope, a reflection of that freedom.
Freedom doesn't equate to truth. On the internet everybody can claim everything.
Especially if you are drawing from anonymous sources. Nobody else can verify those. And can you be sure that you aren't used as a tool for disinformation?
Relevant (accurate) past recognition should be taken into account as a prior when evaluating uncertain present claims. It doesn’t mean they’re automatically right, and evidence/arguments should be evaluated on their own merit as much as possible, but in the face of opaque fog of war, are you suggesting this journalist should be taken no more seriously than some rando off the street?
> What’s next - Einstein’s Nobels are also proof by authority?
If you use them as an argument for Einstein's later work, then yes. Einstein's later work for example for black holes was completely wrong.
Knee-jerk reaction?
It's not offered as proof, it's offered in the standard way reputation works...
So I wouldn't call it a knee-jerk reaction when I consider what he says as basically being "trust me bro".
I would go even further and say that if his story was sound he wouldn't need to write a defense on why he's published it on Substack. If it were sound it wouldn't matter if he published it on Twitter or Substack or if he published it in the Playboy or The New York Times.